THE Lin family murders were triggered by the “sexual motive” and grooming of a young female relative by the accused killer Robert Xie, a Supreme Court jury has been told.

The explosive new evidence — revealed by the state’s senior Crown prosecutor Mark Tedeschi QC on the second day of his opening address — included “a clear sexual interest” in the young woman, which allegedly evolved into outright abuse, and that murders were committed so the woman would have to live under his roof.

Robert Xie arrives at King St Supreme Court today for the second day of his retrial over the murder of five members of the Lim Family at their Epping home. Picture: Stephen CooperSource:News Corp Australia

The 50-year-old has pleaded not guilty to murdering his brother-in-law, newsagent Min “Norman” Lin, Min’s wife Lilly, her sister Irene, and Min and Lilly’s two sons Henry and Terry on July 18, 2009. All five relatives were “battened to death” in the bedrooms of the North Epping home in a crime that shocked Sydney.

Mr Tedeschi told the jury the “sexual motive” was one of three reasons Xie, who lived around the corner from the family, killed; alleging he was also spurred on by a “loss of face” with his in-laws and a desire to take over the prized family asset, the Epping Central Newsagency.

The Supreme Court jury was told that, in the 12 months leading up to the murders, “the accused engaged in ­inappropriate sexual behaviour ... on occasions he and (the young girl) were alone and were unlikely to be disturbed”.

Mr Tedeschi said this ­included “stroking her on her thigh when she was wearing shorts”, “rubbing her up and down the side of her body for more than 30 seconds” and holding her so she could feel his groin area.

Xie’s barrister Graham Turnbull SC told the jury the girl “made these allegations very, very recently” and it would be for the court to decide “whether or not they are true”. “The question will be one of her reliability,” he said.

Xie is standing trial on the murder charges only, with no sexual assault ­offence added.

The jury was told that after the murders, the “grooming” and “clear sexual interests” developed into “incidents” happening as often as twice a week.

Distraught Lin family members leave the Supreme Court in June after an earlier hearing into the 2009 murders of the Lin family in Epping. Picture Cameron RichardsonSource:News Corp Australia

Mr Tedeschi said there would be allegations Xie subjected her to “digital penetration” and attempted to have sex with her.

The girl spoke with police in May this year.

Mr Turnbull told the jury the expected four months of evidence would see them exposed to crime scene photographs that would “shock you emotionally” and potentially result in a “desire to punish”. He urged them “to avoid emotion, to avoid prejudice” and consider all the material objectively.

It is alleged that Xie feared “loss of face” because his in-laws championed the work ethic of Min and Lilly, and disapproved of him and Kathy not being in full-time employment.

Mr Turnbull asked Xie to stand in the dock and reveal his slight 170cm, 63kg frame to the jury. He said they would have to consider, when presented with the graphic photos of the injuries, whether “an amateur could do such a thing”.

“You will see (the victims) in the most hideous of circumstances,” he said.

The jury was told Xie hatched plans with his cellmate to ensure he was cleared of the crime, with a scheme involving a corrupt police officer planting evidence on a dead Asian male at a funeral home. Witness A had already approached police by this time with claims about Xie’s confessions, and was co-operating with officers